Abstract
In this paper, we report for the first known time the feasible and realible method for the laser absorption tomographic imaging based on the optical heterodyne technique that has very high sensitivity and excellent directivity to distinguish one specific direction from another. This new method is named the Coherent Detection Imaging(CDI). For the establishment of laser absorption tomography for biomedical applications on the basis of the projection slice theorem, the following four fundamental conditions should be satisfied basically ; 1) detectable optical transmittance through living tissues and systems, 2) excellent detectivity to distinguish a directly transmitted beam component from widely dispersive multiple scattering of light, 3) establishment of the Lambert-Beer's law for the directly transmitted beam component, and 4) existence of straightly propagated beam component even in the presence of complex distributions and boundaries of refractive index in the medium.
We have experimentally demonstrated the fullfillment of these fundamental conditions to establish the CDI method in highly scattering absorptive media. Thus the first successful tomographic image reconstruction was achieved using actual in vitro biological objects.
